Poly(vinyl alcohol) is useful for many purposes. For example, poly(vinyl alcohol) of especially high viscosity is used as thickening agent, protective colloid and the like in which high viscosity solutions having low solid content are desired. Moreover, poly(vinyl alcohol) is used in textile and paper sizing, in adhesives, as an emulsion polymerization aid, and as an intermediate in the production of poly(vinyl butyral), the adhesive interlayer in laminated safety glass. Furthermore, poly(vinyl alcohol) is used for textile fiber after water-insolubilization.
High molecular weight poly(vinyl alcohol) is a high-melting, high-strength material which is suitable for a wide variety of applications including tire cord, housing materials, automotive plastics, super strength fibers, and the like. The excellent adhesive properties of poly(vinyl alcohol) render it potentially an outstanding tire cord material.
Poly(vinyl alcohol) is conventionally produced in a two-step process. In the first step of the process, vinyl acetate is polymerized to produce poly(vinyl acetate). In the second step, the poly(vinyl acetate) is subjected to alcoholysis (methanolysis or ethanolysis) in order to convert the poly(vinyl acetate) to poly(vinyl alcohol).
In the production of poly(vinyl alcohol), byproducts and unconverted reactants are produced. The need remains for using and recycling these byproducts and unconverted reactants.